Leptin and leptin receptor involvement in cancer development: a study on human primary breast carcinoma

Abstract

Obesity is associated with an increased risk of breast cancer. Leptin, a hormone synthesised essentially by adipose tissue, may be involved in cancer development. We examined the expression of leptin and leptin receptor (Ob-R) in human primary breast cancer and adjacent non-cancerous tissue. We also analysed their relationships with histological variables such as the oestrogen and progesterone receptors, Ki67 proliferation factor and tumour size. The expressions of leptin and Ob-R were investigated by immunohistochemical staining in 35 primary breast cancers and 17 adjacent non-cancerous tissues. Samples and histological features were obtained from the Anti-Cancer Centre. Expressions of leptin and Ob-R were detected in, respectively, 85 and 75% of the primary breast cancer cases studied. The expression of leptin was significantly correlated with Ob-R detection (p=0.008). In addition, Ob-R expression in primary breast carcinoma was positively correlated with oestrogen receptor expression (p=0.028) and tumour size (p=0.045) but not with Ki67 or progesterone receptor expressions. However, the expression of leptin showed no statistical correlation with these variables. First, the co-expression of leptin and Ob-R in primary breast cancer shows that leptin acts on mammary tumour cells via an autocrine pathway. Second, the co-expression of Ob-R and oestrogen receptors suggests a possible interaction between leptin and oestrogen systems to promote breast carcinogenesis. Finally, the fact that Ob-R expression was positively correlated with tumour size may point to a potential role of leptin as a growth factor and of Ob-R as a new prognostic factor.

IL‐1 family in breast cancer: Potential interplay with leptin and other adipocytokines

“…Both leptin and ObR expressions are more abundant in tumours with a high grade [57]. Interestingly, leptin and ObR are co-expressed in primary breast carcinoma, suggesting that leptin acts on mammary tumour cells via an autocrine pathway [55].…”

“…We have recently investigated leptin and ObR expression in vivo in epithelial or ductal tissues of breast tumours [53][54][55]. We have identified leptin as a proliferative factor in human breast carcinoma since immunohistochemical expression of leptin on biopsies correlates with the different stages of tumour invasion in ductal tissues [54,55]. In addition, leptin is not expressed in healthy breast tissue [54] but is detected in normal tissue adjacent to ductal carcinoma, suggesting leptin may be a prognostic marker of early tumourigenicity in human ductal breast carcinoma.…”

Involvement of adiponectin and leptin in breast cancer: clinical and in vitro studies

“…Antigen retrieval was performed for AdipoR1 and AdipoR2 localization. The immunohistochemical procedure was performed as previously described (Jarde et al 2008a).…”

“…Korner et al (2007) reported that AdipoR1 and AdipoR2 proteins were detected in 30.4 and 26.3% of breast cancer biopsies respectively. In previous studies, we demonstrated that leptin and leptin receptor (Ob-Rt) were involved in breast cancer, since both markers were expressed in mammary tumor (Caldefie-Chezet et al 2005, Jarde et al 2008a.…”

Effects of Obesity and Obesity-Related Molecules on Canine Mammary Gland Tumors

“…25 Leptin, one of the representative hormones released from adipocytes, stimulates the proliferation of breast cancer cell lines by upregulating the transcription of aromatase. 18,21 The levels of circulating leptin correlate with adipocyte accumulation in both humans and dogs. 17,40 Recently, the role of leptin in human breast cancer was investigated.…”